De Benneville had a mystical experience and later a near death experience which he described in The Life and Trance of Dr. George De Benneville. These experiences convinced him that Hell is for purification, not punishment, and that, ultimately, all will be united with God. He believed that God is absolutely good and in his love would never condemn any human to eternal damnation. He also preached that each human being has a dualistic nature; the outer, flesh-and-blood person is subject to the evils of the world and may choose to do good or to do wrong, while the inner, spiritlike person is crafted by God and is perfect, immaculate, and holy, and cannot be damned. Therefore, all human beings experience salvation.